Problem: Simplify the following expression: $x = \dfrac{1}{10p} - \dfrac{8}{3p}$
Answer: In order to subtract expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $10p$ and $3p$ $\lcm(10p, 3p) = 30p$ $ x = \dfrac{3}{3} \cdot \dfrac{1}{10p} - \dfrac{10}{10} \cdot \dfrac{8}{3p} $ $x = \dfrac{3}{30p} - \dfrac{80}{30p}$ $x = \dfrac{3 -80}{30p}$ $x = \dfrac{-77}{30p}$